Diversified miner Rio Tinto and energy group Edify Energy have entered into two new solar and battery hybrid services agreements (HSAs) to enhance the supply of reliable, competitively priced electricity to the Gladstone aluminium operations in Queensland. 

The agreements, announced this week, will see Rio Tinto purchase 90% of the power and battery storage capacity generated by the Smoky Creek and Guthrie’s Gap solar power stations over a 20-year period.

Under the terms of the deal, Edify Energy will design, build, own, and operate both solar projects, with construction set to begin in late 2025 and targeting completion in 2028. The Smoky Creek and Guthrie’s Gap solar power stations will be located in Central Queensland, featuring a combined 600 MWac of solar capacity, alongside 600 MW of battery storage, capable of storing up to 2 400 MWh of energy.

“These agreements are integral to repowering our Gladstone aluminium operations with affordable, reliable and lower carbon energy for decades to come,” Rio Tinto Australia CEO Kellie Parker said. “For the first time, we have integrated crucial battery storage in our efforts to make the Boyne aluminium smelter globally cost-competitive, as traditional energy sources become more expensive.”

The project comes as part of Rio Tinto's broader strategy to transition to renewable energy. The two solar stations will complement Rio Tinto’s previously announced renewable-energy agreements, including the 2.2 GW of renewable wind and solar power purchase agreements signed in 2024 for its Gladstone operations. Together, these four projects will secure a total of 2.7 GW of future wind and solar energy in Queensland, with an expected 80% of Boyne smelter’s annual electricity demand being supplied by these renewable sources.

Edify Energy CEO John Cole said the collaboration with Rio Tinto was a commitment to supporting the sustainable future of Australia's industrial sector. 

“The Smoky Creek & Guthrie’s Gap solar power stations deliver the latest in solar, battery and inverter technology to support Australia’s power needs,” Cole said. “We are proud to advance Rio Tinto's goals to repower its Gladstone operations and to play a role in the transition to a low-carbon economy.”

The agreements are set to have a transformative impact on emissions at Rio Tinto's operations. With the four contracted projects combined, Rio Tinto expects a 70% reduction in the Boyne smelter’s Scope 1 and 2 emissions by 5.6-million tonnes of CO₂-equivalent a year.

As part of the Smoky Creek & Guthrie’s Gap agreements, Rio Tinto’s 90% share of the battery storage system capacity will amount to 2 160 MWh, providing about 30% of the firming required to repower the Boyne smelter with renewable energy. The battery storage will store green energy for use during peak demand periods or low solar output, contributing to the overall stability and resilience of Queensland’s power network.

Rio Tinto’s aluminium production chain in Queensland remains a key economic contributor to both the state and the nation. The company’s operations in Gladstone directly employ more than 4 500 people, with 3 000 of those jobs based in the region, including 1 000 at the Boyne smelter. Rio Tinto’s three production assets in Gladstone include the Boyne aluminium smelter, the Yarwun alumina refinery, and the Queensland alumina refinery.